1. V-T To nullify a legal decision or procedure means to declare that it is not legally valid. 使失去法律傚力[正式]

They knew the courts could nullify the marriage before the ink was dry. 他們知道法庭可以在簽訂婚約的墨汁未乾之前，宣佈婚姻無傚。

2. V-T To nullify something means to make it have no effect. 使無傚[正式]

A missing or illegible name will nullify your vote. 遺漏或字跡難以辨認(rèn)的名字會(huì)使你的投票無傚。